1. Field of the Invention
The present invention relates to an optical code reader, and more particularly to a scanner which scans bar codes given on the surface of paper.
2. Description of the Prior Art
As a bar code scanner of this type, those shown in FIG. 3 and FIG. 4 are already known. Namely, in these figures, numeral 1 represents a lower case; 2, an upper case which encases the scanner mechanism by engaging with said lower case. At the upper surface of this upper case 2, a window hole 4 is formed in order to allow a switching operation body 3 to be exposed to the outside.
Numeral 5 represents a sensor which is held at the front end by the lower case 1 and the upper case 2. This sensor 5 provides, as shown in FIG. 4, the vertical split type base bodies 5a, 5b and the end point formed by such base bodies 5a, 5b is tapered with the end point designed smaller in diameter in order to hold a ball lens 6. Numeral 7 represents an optical fiber of which end corresponds to to the ball lens 6 and rear end is branched in the form of letter Y. At the branching end of this fiber 7, an LED which will become a light emitting element and a phototransistor which will become a light sensing element are respectively arranged.
Moreover, numeral 8 represents a stopper which engages with the lower case 1 and the upper case 2 and fixes the end points of them. This stopper 8 is provided with a through hole 8a at the center thereof allowing the end part of sensor 5 to pass through. At the end front end of this stopper 8, a cap 9 having the almost conic external shape is fixed by threading. The end point of sensor 5 is housed within this cap 9. A small hole 9a for allowing the light to pass is formed at the end point of the cap 9 and the ball lens 6 of sensor 5 is placed therein.
Numeral 10 represents a circuit substrate and numeral 11 respresents a wire.
However, the scanner of the prior art uses many components. Therefore, size allowance of such components are added while the components are sequentially assembled and finally it is very difficult to obtain a high accuracy of the distance between the end point of sensor and the end point of cap which will be in contact with the surface of paper.